Apparatus of this type are known and essentially include an endless screw driven by an electrical motor turning in a cylinder at one of the ends of which a feed hopper enters, the other end being obstructed by a grille penetrated by holes of a predetermined diameter. The archimedian screw ensures both the transport of the paste introduced into the hopper and the pressure necessary to press the paste through the grille. Similar devices are also used for mincing meat.
Kitchen apparatus are also known which by the addition of an appropriate attachment carry out any one of a great number of functions such as mincing, chopping, grating, etc. One such apparatus is described in French Pat. No. 7127039. This apparatus is made up of a stand enclosing an electric motor on which is added a removable bowl, the motor not being able to be operated unless the bowl is properly mounted on the stand and is closed by a lid. The functioning of this apparatus is thus very foolproof. However, because of the various jobs to be done by the apparatus the electric motor turns at about 1500 revs per minute whereas for an apparatus for the extrusion of food paste the speed of rotation of the screw should be about 30 revs per minute.